Triphenylmethane compound and method of producing same



Patented Sept. 23, 1924.

UNITED STATES PATENT OFFICE;

DON W. BISESELL AND ROBERT B. MCCANN OF BUFFALO, NEW' YORK, ASSIGNORS' TO NATIONAL ANILINE & CHEMICAL COMPANY, 1131 3., OF NEW YORK, N. Y., A COR- LPORATION OF NEW YORK.

TRIPHENYLMETHANE COMI?OUND AND METHOD PRODUCING SAME.

No Drawing. Application filed l lovember To aZZ whom it may concern.

Be it known that we, Don TV. BISSELL and Runner B. MCCANN, citizens of the United States, and residents of Buffalo, in the 5 county of Erie and State of NewYork, have invented certain new and useful Improve ments in Triphenylmethane Compound and h lethods of Producing Same; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved method of condensing meta-hydroxybenzaldehyde with diethylanilin, and sulfonating the condensation product thus produced, with the resulting production of new disulfonic acid of 3-hydroXy-l 1 '-tetraethyldiaminotriphenylmethane. The new sulfonic acid, as well as the improvements in the method of its production, forms a part of the invention.

The invention will be'further illustrated by the following specific examples:

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Example 1: 120 pounds of 66 Be. sulfuric acid are slowly added to 3458 pounds of diethylanilin, with agitation in a cast iron kettle, and the contents being kept cool so that the temperature does not rise above 60 C. When all of the acid is added. and the temperature of the mixture begins to fall, 135 pounds of pure dry ineta-hydroxybenzaldeliyde are added, care being taken that the agitation continues and that the temperature does not rise above 100 C. The mixture is then heated, with continued agitation, for 2 1 hours at a temperature of 100 to 105 3., for 24 hours at 105 to 110 (1., and then for 24 hours at 115 to 120 C, the total time of heating being about 72 hours. The contents of the kettle, without cooling, are then dumped into a-large iron pan, allowed to cool, and then broken up into lumps and ground to a coarse powder. The condensation product, namely, the hydroxyl. l -tetraethyldiaminotriphenylmethane, is thus obtained in the form of its sulfate, and this sulfate, without conversion into the free base, is utilized directly for the sultonation.

29, 1920. Serial No. 427,127.

and above that required for the condensation has the advantage of keeping the prodnot more fluid and of lessening the danger of charring.

It has beenfound possible to use less sulfuric acid than is used in the above example. provided the condensation be allowed to cover a longer period of time, and this smaller amount of acid has the advantage of leaving the product still more fluid, es pecially at the end of the operation, at which time it is then more easily handled. This use of a smaller amount of acid is illus'trated by the following example:

Example 2: 413 pounds of diethylanilin are charged into a jacketed kettle provided with an agitator, 81 pounds of 66 sulfuric acid are then added, and the mixture agitated for about 2 hours. 155 pounds of metahydroxylbenzaldehyde are then added while the temperature is kept below C. and. the charge is agitated at such temperature for 1 hour. It is then heated to 100 to 105 C and kept at that temperature for 24L hours; it is next kept at 110 C. for 48 hours; and it is finallyimaintained at 115 C. for 18 hours. The charge is then dumped into pans, the pans covered to keep out moisture, and the product allowed to cool in the sulfonation of 3-hydroXylA- tetraethyldialninotriphenylmethane it has heretofore been proposed to isolate and purify the free base. This isolation and purificatiomhowever, is attended with considerable difficulty. lVe have found that the isolation and purification of the free base is not necessary, and that the crude sulfate, produced as above described, can with ad vantage be used directly for the subsequent sulfonation, thereby avoiding the additional steps necessary in freeing and purifying the base and subsequently dissolving it, while at the same time taking advantage of the sulfuric acid remaining from the condensation. The crude condensation product, when cold. is brittle, easily powdered, does not require drying, and is easily soluble in the oleum used for its sulfonation.

In carrying out the sulfonation, we have found it of advantage to add oleum in successive portions, instead of all at once. The first portion acts as a solvent, to dissolve the sulfate of the 3-hydroxy-t.l-tetraethyldiaminotriphenylmethane, while it also effects considerable sulfonation, and it enables proper conditions to be readily obtained for completion of the sulfonation upon the subsequent addition of the rest of the oleum. By proceeding in this waythe concentration of sulfur trioxide is kept down. The sulfonation process will be further illustrated by the following specific example Example. 3: In a water jacketed cast iron kettle, fitted with an agitator, 73 pounds of 66 sulfuric acid are mixed with 161.5 pounds of 26% oleum, and the mixture is cooled to125 C. To this. mixture. there is slowly added 100 pounds of the powder-ed crude product obtained according to example 1 above, by the condensation of metahydroxybenzaldehyde with diethylanilin, carebeing taken that the temperature does not rise above 30 C. After all of the condensation product is added, pounds more of the. 26% oleum is run in while keeping the. temperature below, 30 C., and the agitation is continued for 48 hours at a temperature of from 23 to 27 C. The sulfonation mixture is then added to 1000 pounds of water in a lead-lined kettle fitted with an agitator, the mixture being added to the agitated water in a steady stream. while the temperature rises to about 60 to C. The resulting solution is then stirred for 2-4- hours during which time it cools: to room temperature and the disulfonic acid of the I base separates out as a. hydrate in fine white to grayishwhite crystals, 500 pounds more of water are added, the mixture thoroughly agitated, and then filteredthrough a filter press, the crystalline precipitate being washed in the press with 200 pounds of water and air being then forced through it for a few minutes. The crystalline product is then taken from the press and put back into the lead-lined kettle and agitated again with 500 pounds of water, filtered. washed with of the condensation product, produced ac-- cording to example 2 above,'are then added. slowly with COOllIlP', while keepinn'the temperature below 30 C. 60 pounds of 90% t oleum are then added. then 30% pounds of the comiensation product, and again (ill pounds of oleum, and so on, until all the condensation product, amounting to about 290 pounds, is added. Finally the remainder of the oleum, sufiicicnt to bring the total up to about (54-0 pounds, is run in and the tvmperature is maintained at 2.3" for 48 hours. The product is then transferred to a le-adlined vat containing 3000 pounds of water and allowed to crystallize for 2t hours. 1500 pounds more of water are then added and the charge. is filtered in a filler press and washed in the press with water until most of the acid. is removed, after which air is forced through the press for about 20 minutes. The leuco disulfonic acid is thus obtained as a press-cake containing sufiicient water to form about a 70% paste. This product can be further dried, or it can be directly used for the production of a dyestutf, by subjecting it to oxidation.

The product obtained according to examples 3 and 4 is, when pure, white and crystalline, only slightly soluble in water and dilute acids, but readily soluble in alkali solutions with the formation of a soluble salt. it requires ajiiproxiinatcly 2 equivalents of caustic soda to dissolve it, thus indicating that it is a dibasic acid, while its sulfur content has been found to COII'OSI'XH'Nl to that of the disnlfonic acid. \Vhen first produced. it contains water of crystallization. a part or all of which it slowly lose-s by clllorcsccncc at ordinary temperatures. It easily gives ofl all of its water without melting at about 70 C. and forms a very fine powder which easily passes back into the hydrated crystal form when. treated with water. The anhydrous product, well as the hydrated product. is only slightly soluble in water. The. anhydrous form melts at about 282 to 282.5 C.

This product we consider to he a ncw product. and we accordingly claim it as a part of the invention.

e claim:

1. The method of effecting the preparation and sulfonation of 3'hydroxy-4'A"- tetraethyldiaminotriphenylmethane, which comprises subjecting nieta-hydroxylienzuldehyde and diethylanilin to condensation with sulfuric acid, and subjecting the resulting condensation product, without isolation of the free base and without separation from the sulfuric acid, to sulfonation.

2. The method of effecting the preparation and sulfonation of 3-hydroxy-4A"- totraethyldiauiinoiriphcnylmcthane, which comprises subjectin; meta-hydroxybenzaldehydc and diethylanilin to condensation with sulfuric acid, cooling and pulveriziing the resulting; product and subjecting it directly to SUlffOl'ltllllOfi with oleum, whereby the I-l-hy- (ll'(l. .y-{l: .':l' tctraclhyldiauiinotriplicnylmchane is obtained in the form of its sulfonic acid Without intermediate isolation of the free base.

The method of sulfonating S-hydroxy- 44 i tetraethyldiaminotriphenylmethane, which comprises subjecting the sulfate of 3 hydroXy lC l tetraethyldiaminotriphenylmethane to sulfonation with oleum.

41:. The method of sulfonating 3-hydroxy- -ld tetraethyldiaminotriphenylmethane with oleum, which comprises adding the oleum in successive portions While maintaining the temperature below about 30 C.

5.,The method of isolating the sulfonic acid of 8-hydroxy-il4"-tetraethyldiaminotriphenylmethane from the product of the sulfonation, which comprises mixing the sulfonation product with a large amount of Water and separating the sulfonic acid in a crystalline state by cooling.

6. The method of preparing a sulfonic' acid derivative of ZB-hydroxy-dd-tetraethyldiaminotriphenylmethane, Which comprises subjecting the reaction product, resulting from the condensation of meta-hydroxy-benzaldehyde and diethylanilin by means of sulfuric acid, directly and Without isolation of individual products of reaction to sulfonation, the sulfonation being effected by adi'nixing the reaction product in succes sive portions and in alternation with successive amounts of the sulfuric acid.

7. As a. new product a sulfonic acid of 3 hydroxy 4.4- te-traethyldiaminotriphenylmethane, said product, when freshly prepared, being a White crystalline solid containing Water of crystallization, but readily giving off its Water of crystallization Without melting When heated and forming a fine powder, said product being only slightly soluble in water and dilute acids, but dissolving easily in alkali solutions and. requiring approximately two equivalents of caustic soda for its solution.

8. The method of preparing 3-hydroxy- 4;.4 tetraethyldiaminotriphenylmethane disulfonic acid, which comprises subjecting 3 hydroxy 4C4! tetrae-thyldiaminotriphenylmethane, as sulfate, to sulfonation With oleum, adding the resulting sulfonation mixture to Water and crystallizing therefrom the 3 -hydroxy l'At" tetraethyldiaminotriphenylmethane disulfonic acid, and subsequently removing the crystalline precipitate by filtration.

9. In the method of preparing 3-hydroxy- 47f tetraethyldiaminotriphenylmethane disulfonic acid by sulfonation of 3hydroXy- 4 4 tetraethyldiaminotriphenylmethane, the step which comprises the crystallization of 3-hydroXy-tA"-tetramethyldiaminotriphenylmethane disulfonic from an aqueous solution of the resulting sulfonation admixture.

In testimony whereof We aiiiX our signatures.

DON W. BISSELL. ROBERT B. MoCANN. 

